Abstract : The following conclusions concerning light reflectance from tree foliage in the wavelength region from 400 to 700 millimicrons were drawn from this study: (1) Tree foliage becomes less reflective as it matures, up to the point where fall coloration reveals distinct changes in leaf pigmentation. (2) New pine needles are more reflective than one-year-old needles. The result is a gradual increase in light reflectance from pines during the early part of the growing season. Once the new needles are fully developed, reflectance tends to decrease during the late summer and fall. (3) Reflectance from broadleaved foliage is relatively high when the leaves first develop, declines during the spring and early summer, remains nearly constant or declines slightly during the summer, and increases strongly during the fall color change. (4) Reflectance from tree foliage is influenced by moisture conditions and declines when trees experience moisture stress. (5) Distinct tone contrasts between pines and braodleaved trees in leaf can be obtained most consistently on panchromatic aerial panchromatic aerial photography during the spring, when one-year-old needles dominate in pin pines and new foliage is appearing on deciduous trees. Strong tone contrasts can also be obtained when the broadleaved trees are leafless. (Author)